The systems and methods described herein relate to a flexible heat accumulator for a vehicle engine cooling system.
The heating of the drive train from friction has a large influence on an engine's fuel consumption and emissions. This is because the heat from the drive train effects the generation of the fuel mixture. Drive trains operating below a temperature threshold may experience fuel condensation and uneven air-fuel distribution within the chambers and thus lower efficiency. This effect is most apparent during vehicle cold starts. Normally, a motor vehicle which has been driven and is warm experiences cold start conditions after eight or more hours switched off in a stationary state.
Previous embodiments have employed coolant heat accumulators that store engine heat during travel and may hold this heat for over twenty-four hours after the engine has been turned off depending on the external temperature. If cold start and travel are performed on the following day, the heat that is stored in the heat accumulator is released in a small cooling circuit of the engine and can then shorten the warming up phase of the engine. Faster engine heating decreases the fuel consumption and the quality of the emissions
In some embodiments, this type of heat accumulator is composed of metal and has a cylindrical shape. It may contain an insulation layer which is usually embodied as a vacuum. The fixed structure of this heat accumulator embodiment, dimensions, and weight, contribute to disadvantages during operation of the vehicle.
EP 1 983 167 A1 discloses a heat accumulator that connects a first container to a second container via a spring. The containers have an inner wall, whose shape is congruent to a cylinder wall of an engine. A heater accumulator medium may be within the containers and may cause the containers to expand as the medium absorbs heat. As a result of this expansion the containers are pushed away from the cylinder wall.
JP2010054162A presents a heat accumulator with a plurality of flexible heat accumulator capsules that are arranged in a heat exchange chamber and are placed under pressure with a pressure plate and deformed as heat is absorbed.
U.S. Pat. No. 4,414,932 discloses a heat accumulator that is in contact with the intake manifold in order to store heat and output it again. The heat accumulator may be embodied as a bellows.
The inventors found that a flexible storage container permits a cost-effective and lightweight solution with a saving in weight of approximately 2.5 to 4.5 kg compared to conventional solutions, which lowers the fuel consumption of the vehicle. In addition, unlike the aforementioned heat accumulators, the disclosed embodiment may contain no rigid solid parts. Storage container material flexibility further allows for the containers external shape to be largely freely selected, simplifying the planning of the engine compartment construction.
A disclosed embodiment of a heat accumulator for engine coolant comprises a flexible storage container with an inner body and an outer body, wherein an insulation device is arranged between the two bodies, as well as an inflow and outflow for the coolant. The coolant, for example may be a liquid such as water that may be used to control the temperature of an engine to provide heating and/or cooling. The heat accumulator may be used in passenger vehicles and trucks as well as in other vehicles, such as agricultural implements or in the construction industry, in shipping and aircraft. The coolant may be used for a vehicle engine or for further components of the drive train. Other embodiments of the heat accumulator may be used to heat up batteries of an electric vehicle or to achieve increased performance of the batteries at cold temperatures. In addition, in electric vehicles the heat accumulator may be used to heat the passenger compartment, as a result of which valuable battery energy can be reserved for vehicle propulsion. It should be noted that these applications are also included under the term vehicle engine.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.